In general, in order to provide location services to a user, considerable signaling and location information should be transferred between a mobile terminal and a location server. The so-called positioning technologies have been standardized for providing such location services, for example, a location service based upon the location (position) of a mobile device, are undergoing rapid widespread dissemination.
The positioning technologies can be provided through a user plane and a control plane. A Secure User Plane Location (SUPL) which is well-known as an example of the positioning technologies provides the location services through the user plane.
The SUPL technology is an efficient method for transferring location information required for the location calculation (i.e., positioning) of a mobile station. The SUPL employs a user plane data bearer so as to transfer positioning assistance information such as Global Positioning System (GPS) assistance, and to carry positioning technology associated protocols between the mobile terminal and a network.
In general, a SUPL network associated with location services in the location information system includes a SUPL agent, a SUPL Location Platform (SLP) and a SUPL Enabled Terminal (SET). The SUPL agent refers to a logical service access point using location information which is actually measured. The SLP refers to a SUPL service access point at a network portion where network resources are accessed to obtain location information. The SET refers to a device for communicating with the SUPL network using a SUPL interface, for instance, a User Equipment (UE) of the UMTS, a Mobile Station (MS) of GSM, a IS-95 MS, laptop computers or Personal Digital Assistants (PDAs) which have a SET function, or the like. The SET may also be one of various mobile terminals which is connected through a Wideband LAN (WLAN). The SET supports various procedures defined by the SUPL by being connected to the network via the user plane bearer.
In a mobile communications system such as the location information system, many terminal users desire that different privacy policies be applied according to the current locations of their terminals. That is, a user may want to receive a positioning request notification based on a current location of his terminal so as to restrict the accessing of location information by a third party. For instance, positioning of his terminal can be granted when at home, but may require positioning request notification be performed when he is at work in his office.
Thus, privacy rules may be applied differently according to the user who requests positioning and a location of the SET (e.g., home, office, etc.) in a location information system, for example, a SUPL network. Therefore, if the SET is located within a specific area, before the location of the SET is reported to a user (a third party) who requests positioning, a location server performs an appropriate privacy checking procedure according to the corresponding user and the location of the SET. Preferably, the SET, being a device capable of communicating with the SUPL network, may be one of a User Equipment (UE) of the UMTS, a Mobile Station (MS) of GSM, a IS-95 MS, or the like. In the present invention, the SET will be simply referred to as a terminal.
However, the notification by the location server is simply requested by transmitting a notification element to the SET regardless of the user or location of the SET. Accordingly, there is no way for the SET side to recognize whether the corresponding notification request is performed based upon the location (or based on the user), which results in an unstable system due to an unclear time point of a notification response from the SET.
In a SUPL network structure, only the functions of each SUPL device have been suggested thus far, while a signal transfer system between each SUPL device for transferring location information is still being discussed. Accordingly, needs for the signal transfer system are more brought out.